Battery charge limit systemd service (adjustable)

Just a slight expansion on a Stack Overflow answer.

Save as /etc/systemd/system/battery-charge-limit@.service.

[Unit]
Description=Set battery charge limit to %I percent
After=multi-user.target

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/bin/sh -c 'echo %I > /sys/class/power_supply/BAT0/charge_control_end_threshold'
ExecStop=/bin/sh -c 'echo 100 > /sys/class/power_supply/BAT0/charge_control_end_threshold'

[Install]
WantedBy=multi-user.target

(replace /sys/class/power_supply/BAT0/charge_control_end_threshold with the correct sysfs path for your machine, if applicable)

Usage

Limit the battery to 80%.

# systemctl start  battery-charge-limit@80.service
# systemctl enable battery-charge-limit@80.service

Keep in mind that this service has no way of knowing if 2 instances of itself exist, that’s to say, the following situation isn’t prevented by systemd:

# systemctl enable battery-charge-limit@80.service
# systemctl enable battery-charge-limit@50.service